In recent years, large-capacity storage apparatuses have been used to manage large amounts data in enterprises and so on. Such storage apparatuses are configured by arranging a multiplicity of storage devices as an array, and the storage devices are each operated using a RAID (Redundant Array of Independent Inexpensive Disks) system, for example. At least one or more logic volumes (hereinafter referred to as ‘logical volumes’) are formed in a physical storage area provided by a storage device group, and these logical volumes are provided to a host apparatus. The host apparatus is able to write and read data to and from the logical volume by transmitting predetermined commands.
As functions which are installed in this storage apparatus, a remote copy function and a flashcopy function are conventionally widely known.
The remote copy function is a function for copying data stored in a storage apparatus in a local site to a storage apparatus in a remote site provided in a location separate from the local site (hereinafter suitably referred to as a ‘remote copy’). As a result of this remote copy function, data backups in the remote site are possible and data loss can be prevented even if a fault is generated in the local-site storage apparatus due to an earthquake or fire or the like.
Furthermore, the flashcopy function is a function for copying data stored in a storage area designated by a host apparatus in a logical volume provided in the storage apparatus to another logical volume in the same storage apparatus (hereinafter suitably referred to as a flashcopy). As a result of this flashcopy function, a static data image (hereinafter called a ‘snapshot’) of a storage area in a flashcopy target at the point when flashcopy execution is started can be saved in the other logical volume.